Validation of a drug-based score in advanced urothelial carcinoma treated with pembrolizumab.

Aim: To validate a 'drug score' that stratifies patients receiving immunotherapy based on concomitant medications (antibiotics/proton pump inhibitors/corticosteroids) in urothelial carcinoma (UC). Materials & methods: We assessed oncological outcomes according to the drug score in 242 patients with advanced UC treated with pembrolizumab. Results: The drug score classified patients into three risk groups with significantly different survivals. Heterogeneous treatment effect analyses showed that the primary cancer site (bladder UC [BUC] or upper-tract UC [UTUC]) significantly affected the prognostic capability of the drug score; it significantly correlated with survivals in BUC, while there were no such correlations in UTUC. Conclusion: A drug score was examined in advanced UC treated with pembrolizumab and was validated in BUC but not in UTUC.